To develop a theoretical framework for explaining the observed change in demand for human skill and knowledge that occurs with economic growth, a macroeconomic analysis was made of economic variables which are influenced by political, social, and cultural factors. In the three-dimensional framework, total output (Y) of all final goods and services produced in the economy during one specified time period is treated as a function of three inputs, capital (K), labor (L), and natural resources (R). Because the framework contains only four variables, an entire economy can be theoretically analyzed. Thus, to demonstrate how the need for human skill and knowledge is generated, an analysis of economic development reveals that as more complex forms of non-human capital are required, more human capital is also required. The demand for human skill and knowledge is largely a function of factor disproportions among the basic inputs, K, L, and R which generate certain basic forces. (SB)